Only in the first episode! the entire episode basically revolves around sacrificing animals, deel free to skip it, the episodes are all their own stories. The series is still good :). but its death is pretty saddening if you're sensitive to that, a woman stabs her family pet. it doesn't directly show the wound however blood flies onto the woman's face and you hear it cry out.
Episode named 'Lab rats' right at the end the guy in the gas chamber is heavily foaming at the mouth and does bend/keel over with audio. It's not v and doesn't look or sound like it but still slightly distressing/gross to watch if you're extremely sensitive to v.
Rats, one in the first episode (or maybe it's a very large mouse ??) but then three more in the forth. All are killed. the first is by hand but the rest are gassed (their bodies are shown with bloodied faces though)